April 13, 2005

It pays to read the news closely.

Like with theis story. On the surface, it seemed to be a typical piece about a newly discovered health hazard. But, as often seems to be the case in newspapers, the real story got buried in the middle.

According to a new study to be published in the journal Environmental Health Perspectives, there is increasing evidence that a chemical commonly used in plastic bottles and food packaging may be harmful in small amounts. After reviewing over 100 studies of the risks of bisphenol A, the authors of the study are asking the US Environmental Protection Agency to consider restricting use of the chemical.

Bisphenol A, or BPA, has been detected in nearly all human bodies tested in the United States. It is a key building block in the manufacture of hard, clear, polycarbonate plastics, including baby bottles, water bottles and other food and beverage containers. The chemical can leak from plastic, especially when containers are heated, cleaned with harsh detergents or exposed to acidic foods or drinks.

The leakage is a problem because BPA is a chemical that can mimic human sex hormones. Such compounds have been shown to affect the development of reproductive systems and brains in newborn animals  and there is evidence that they are doing the same to humans, especially young ones. The 100-plus studies done on the chemical have had mixed results, however, with some showing BPA has no effects at low levels, and a larger number showing that it harms lab animals those same levels.

But, at least for this magpie, the crux of the story is in these paragraphs:

In an interview yesterday, [study co-author Frederick] vom Saal, a reproductive biologist at University of Missouri, Columbia, said there is now an "overwhelming weight of evidence" that the plastics compound is harmful.

"This is a snowball running down a hill, where the evidence is accumulating at a faster and faster rate," vom Saal said. "You can't open a scientific journal related to sex hormones and not read an article that would just floor you about this chemical. ... The chemical industry's position that this is a weak chemical has been proven totally false. This is a phenomenally potent chemical as a sex hormone."

In their study, vom Saal and Hughes suggest an explanation for conflicting results of studies: 100 percent of the 11 funded by chemical companies found no risk, while 90 percent of the 104 government-funded, nonindustry studies reported harmful effects. [emphasis added]

What a coincidence, huh?

Of course, the industry mouthpieces have the usual answer:

Steven Hentges, executive director of the polycarbonate business unit of the American Plastics Council, said yesterday that the new report lists numbers of studies and pieces of data without analyzing them to determine their strengths or weaknesses and relevance to human beings.

"The sum of weak evidence does not make strong evidence," Hentges said. "If you look at all the evidence together, it supports our conclusion that BPA is not a risk to human health at the very low levels people are exposed to. This paper does not change that conclusion. It has an opinion, not a scientific conclusion."

Just like all those papers saying that global warming exists are just expressing an opinion, we imagine.

So what we have here is another scientific 'controversy' that isn't. The reason that the plastics manufacturers can assert that there's a doubt about the dangers of BPA is that they've funded scientific studies to 'prove' the conclusion they want: that BPA is not dangerous. The fact that almost all of the non-corporate studies found just the opposite speaks very loudly, we think.

As a species, we're pretty hard to tweak with hormones, and even then.

Really? I don't want to weigh in on how harmful BPA is, but do you really think that it is hard to tweak humans with hormones? Really? OCPs are naught but hormones, and they do a lot of tweaking. There was the rush to use HRT because of the expected benefits, and then a rush from it because of all the negative consequences. Hormones control dwarfism and gigantism. Diabetes is a disease of the hormones. Research has shown that in mixed-sex twins, the effect of intra-unterine hormones can be lifelong. And in all of these cases, the amount of hormones involved is incredibly minute.

So can you explain . . ?

Posted by: jbbuhs at April 13, 2005 06:09 PM

As a species, we're pretty hard to tweak with hormones, and even then...

What is needed is more chemical analysis of the interactions...
Posted by: Crissa at April 13, 2005 05:40 PM

what the hell are you babbling about? as a species, we've beeen designed to respond quite acutely to miniscule doses of small molecular and hormonal regulation.

the point is that 11/11 studies funded by chemical companies contradict 93/104 publically-funded studies, and the EPA erred on the side of the chemical companies.